Occupant restraint system located in the rear passenger compartment of a motor vehicle

ABSTRACT

In order to provide an occupant restraint system located in the rear passenger compartment of a motor vehicle, which system increases the safety of vehicle occupants and at the same time can be produced simply and therefore cost-effectively, an occupant restraint system located in the rear passenger compartment of a motor vehicle, having a side airbag module which comprises a gas bag and a gas generator and is arranged next to that side of a rear seat which faces the side body is proposed, a cover being provided in front of the side airbag module in the direction of travel, and the cover consisting of elastically deformable material and being an integral component of a side member of the rear seat or of an arm support arranged in the region of the side body.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a national phase of International Patent ApplicationNo. PCT/EP02/06025, filed Jun. 1, 2002, designating the United States ofAmerica, and published in German as WO 03/013914 A1, the entiredisclosure of which is incorporated herein by reference. Priority isclaimed based on German Patent Application No. 101 37 824.6, filed Aug.2, 2001.

BACKGROUND AND SUMMARY OF THE INVENTION

The present invention relates to an occupant restraint system located inthe rear passenger compartment of a motor vehicle.

If, some time ago, airbags were still special equipment features ofmotor vehicles, in particular of the superior class of vehicles, it iscustomary today that, even in the case of relatively small vehicles, atleast one airbag, namely a front airbag in the steering wheel region andoptionally a passenger's front airbag, is included as standardequipment.

This also applies increasingly to side airbags which are likewisepassive restraint components assigned to a particular vehicle seat. Theairbag, in response to a release signal, suddenly is filled with gas,and is deployed between the occupants and the side vehicle body in orderthereby, in the event of an impact or other accident, to protect theperson sitting in the particular vehicle seat.

In practice, it is generally customary to provide a vehicle seat in sucha manner that a seat back has at least one cushion, for example made offoam, which is arranged in front of a seat structure, as seen in thedirection of travel, and is enclosed by a fabric. In this case, thefabric runs around the seat structure which is arranged in the seatback. The seat structure serves to stabilize the seat back andcustomarily consists of a profiled plate.

As a rule, a side airbag module comprises a gas generator and a gas bag.If the module is released, then the sensor-controlled gas generatorproduces a gas which fills the gas bag for a brief period, with theresult that, in order to protect the occupant, a balloon-like protectivecushion is formed which immediately becomes slack in order to avoid theoccupant impacting against the cushion being thrown back violently. Thesensor connected to the side airbag module can be both impact-controlledand can also be based on a precrash sensory mechanism.

EP 0 919 365 A1 discloses an occupant restraint system located in therear passenger compartment of a motor vehicle, in the form of a sideairbag module which is arranged in a vehicle seat. In this case, theairbag module is fastened to the seat structure and is covered with acushion and a fabric. If the airbag is deployed in response to a releasesignal, in order, in the event of an impact or other accident, toprotect the person sitting in the particular vehicle seat, it has topass through the cushion and fabric. For this purpose, the cushion andfabric have to be designed in such a manner that there is a passage or apassage is formed during deployment of the airbag. The passage is closedduring normal operation of the vehicle and is able to be reliably openedby the force of the deploying airbag. In the prior art, complicatedinstructions are provided for this purpose in the seat structure inorder to tear open the cushion.

The design of a passage of this type is very difficult and very complex.When it is closed, it must not be visible for visual reasons. However,in the event of the airbag being released, it has to be able to beopened reliably and release the airbag. Another complicating factor inthe design of the passage is that the location in the rear seat at whichthe passage is arranged is subjected to severe stress and so the wear ofthe rear seat back also has to be taken into consideration. The airbaghas to be able to emerge just as reliably in the case of a rear seatback which is hardly worn as in the case of a rear seat back which isseverely worn. On the other hand, the passage must also not be visiblein the case of a severely worn rear seat back or even open withoutreleasing the airbag. A further disadvantage of the known solution isthat the opening resistance applied to the airbag is very great, inparticular if an occupant is sitting on the vehicle seat. A large amountof force is therefore necessary to enable the airbag to be able toemerge at all. Added to this is the fact that the structural space in aseat is very restricted, which means that it is very complicated toarrange the airbag in the seat without a vehicle occupant incurring aloss in comfort.

For all of these reasons, it is appropriate to arrange a side airbagmodule next to a rear seat of a motor vehicle. An occupant restraintsystem for the rear seat of a vehicle, in which the airbag module isarranged next to the seat, is disclosed in DE 195 28 627 C1. The knownairbag module is concealed by a flap. That section of the flap whichfaces forward in the direction of travel bears with its free end againsta side body part or panel part, with a gap being formed. The airbag andthe gas generator are arranged in the space enclosed by the flap in sucha manner that the airbag can be brought out through the gap. When theairbag is brought out, the flap is pushed away in the direction of thevehicle occupant.

The flap is designed as a separate component and arranged next to therear seat. It has to be produced separately and fitted in the vehicle.This separate flap therefore requires an increased outlay onmanufacturing and also an increased outlay on installation. This has anegative effect on the production costs of the motor vehicles. Added tothis is the fact that the flap consists, at least in its core, of fixedmaterial which is flexible only to a limited extent—namely a springcore. This core produces the risk of injuries. If, during deployment ofthe airbag, the flap pivots away from the side body or panel in thedirection of the occupant situated on the seat and the occupant moves inthe direction lateral body or panel due to an impact or other accident,the flap is situated right between the occupant and airbag. Depending onwhich position the flap assumes in this situation, there is the risk ofthe vehicle occupant being injured.

Against this background, the invention is based on the object ofproviding an occupant restraint system located in the rear passengercompartment of a motor vehicle, which system further increases thesafety of vehicle occupants and at the same time can be produced simplyand therefore cost-effectively.

This object is achieved by an occupant restraint system located in therear passenger compartment of a motor vehicle, which has a side airbagmodule which comprises a gas bag and a gas generator and is arrangednext to that side of a rear seat which faces the side body. A cover isprovided in front of the side airbag module in the direction of travel,and the cover consists of elastically deformable material and is anintegral component either of a side member of the rear seat or of an armsupport arranged in the region of the side body.

The formation of the cover of the side airbag module from elasticallydeformable material means that the occupant restraint system accordingto the invention which is located in the rear passenger compartment of amotor vehicle affords the advantage that some of the energy which isreleased during the deployment is absorbed by the cover. In other words,the airbag can deposit some of its volume in the deformable material ofthe cover. This prevents the occupant from being injured by thedeploying airbag.

Added to this is the fact that, during deployment, the side airbaginitially presses against the cover. The cover, in turn, thereuponpresses against the occupant who is possibly “out-of-position”. Theoccupant is thereby initially pushed by the cover and then opens up theoutlet for the airbag, with the result that the occupant is alsoprotected by the airbag when he is “out-of-position”. This happens aboveall frequently in the case of children who generally sit on the rearseats of a motor vehicle.

The design of the airbag cover as an integral component of structureslocated in the vehicle also furnishes an advantage with regard to thecosts during installation and manufacturing. The integral formation ofthe cover on a side member of a rear seat does not constitute anincreased outlay in the manufacturing. If the cover is to consist of thesame material as the seat cushion, use has merely to be made of adifferent shape for the production of the cushion. This shape only hasto be changed once and then the outlay on manufacturing is the same. Aconsiderable amount of time is saved on the installation in comparisonwith the prior art because only the seat with its side members has to beplaced into the body. Further steps are not necessary. In contrast withthe prior art, the installation of a separate flap is therefore renderedsuperfluous. The omission of this working step provides considerableadvantages in terms of time and therefore costs, particularly in seriesmanufacturing.

The same applies if the cover is designed as an integral component ofthe arm support. An arm support is generally provided with a cushionextending over the panel attached to the side body. The invention makesprovision for the cushion to be extended to the rear and upward and forit therefore to be able to be used as a cover for the side airbagmodule.

The arrangement of the airbag next to the seat is advantageous becauseconsiderably more space is available there than in a rear seat of avehicle. This ensures a reliable emergence of the airbag because, owingto the larger structural space which is available, the openingresistance is lower in comparison with an airbag which is arranged inthe seat.

The cover preferably consists of the same material as the cushion of theseat and arm support and is also covered with the same fabric. Thisresults, firstly, in the cost-reducing advantages which have alreadybeen explained for the installation and, secondly, in a visuallyattractive interior in which the arrangement of side airbags is notconspicuous because the fabric is matched to its surroundings. A complexconcealment of an airbag cover, as in the case of known airbag lidsintegrated, for example, in a dashboard, is therefore not required.

Provision may be made for the cover, which is an integral component of aside member, to be fastened releasably to the side body or the sidepanel. This has the advantage that a gap which may impair the visualimpression of a vehicle interior is not provided between the seat andpanel.

Below the airbag cover an airbag lid may additionally be provided. Theairbag lid may, however, also be replaced by the cover according to theinvention.

The side airbag module may be fastened, for example, to a partition wallarranged behind the rear seat and, during deployment, may be supportedon the partition wall. The use of the partition wall as a fasteningpoint is advantageous because it is already present and additional,adequately stable fastening devices do not have to be fitted. If thecover is an integral component of the arm support arranged in the regionof the side body, the airbag module can be arranged in the side paneland can be supported on the side panel. In this situation too,additional, adequately stable fastening devices are not necessary.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is explained in greater detail below with reference toexemplary embodiments illustrated in the drawing, in which:

FIG. 1 shows a section through a rear seat and a side panel of a motorvehicle with an occupant restraint system according to the inventionwhich is arranged next to the seat and in which the cover is an integralcomponent of a side member of the rear seat;

FIG. 2 shows a section which corresponds to FIG. 1 and in which thecover is an integral component of an arm support; and

FIG. 3 shows a side view of a rear seat in a motor vehicle with a sidepanel which is arranged behind it and has an occupant restraint systemaccording to the invention in which the cover is an integral part of aside member of the rear seat.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a rear seat 1 of a motor vehicle. The rear seatcomprises a seat structure 2, a seat cushion 3 and a fabric 4surrounding the seat cushion 3. The seat structure 2, which is arrangedin front of a partition wall 5, is used to stabilize the structure ofthe seat 1. The cushion 3 and fabric 4 are used for comfort purposes andfor optimizing the visual impression of the rear seat 1.

A side airbag module 7, which comprises a gas bag and a gas generator,is arranged next to that side 6 of the rear seat 1 which faces the sidebody of the motor vehicle. The module 7 can be fastened to the partitionwall 5 either via a retaining device 8 or preferably directly. Saidmodule is supported on this partition wall 5 during deployment of thegas bag.

The rear seat 1 has an integrally formed extension 11 on its side member9 assigned to the side body. This extension 11 extends from the sidemember 9 of the seat 1 in the direction of the side body and, togetherwith the side member 9, the partition wall 5 and the panel 12 attachedto the side body, forms a cavity 13. The side airbag module 7 isarranged in this cavity 13. The extension 11 forms a cover 11 for theside airbag module 7 in the direction of the vehicle interior. The sideairbag module 7 is aligned in such a manner that the airbag is deployedforward along the side panel or the side body, when looking in thedirection of travel.

The cover 11 consists of the same material as the seat cushion 3 and iscovered with the same fabric 4 as the entire rear seat 1. Owing to thesefacts, the outlay on manufacturing and the outlay on installation arethe same as for simple rear seats without an integrally formed cover.All that is necessary is for the shape to be adapted for the seatcushion 3 and somewhat more fabric to be used. The cover 11 can beprovided only level with the airbag, but there is no problem in alsodesigning the vehicle seat 1 in such a manner that the cover 11 extendsover the entire height of the vehicle seat 1.

In the exemplary embodiment illustrated in FIG. 1, there is a gap 14between the cover 11 and side panel 12. However, provision may also bemade to connect the cover 11 releasably to the side panel 12. Thisreleasable connection has to be designed in such a manner that it can bereliably released by the emerging airbag.

When the signal-controlled airbag is released from the side airbagmodule 13, it pushes against the cover 11. Since the cover 11 consistsof elastically deformable material, it is first of all compressed andthen also pressed against the side in the direction of the vehicleoccupant and therefore opens up the path for the deploying airbag. Ifthe cover 11 is connected releasably to the side panel 12, it has to beopened by the emerging airbag. Owing to the fact that the airbaginitially pushes against the cover 11, some of the energy releasedduring the deployment is absorbed. The airbag can therefore deposit someof its volume partially in the elastically deformable material of thecover 11. This prevents the occupant from being injured by the deployingairbag.

Added to this is the fact that, during deployment, the airbag initiallypresses against the cover 11. The cover 11 in turn thereupon pressesagainst the occupant who is possibly “out-of-position”. The occupant isthereby initially pushed by the cover 11 and then opens up the outletfor the airbag. Injuries to the vehicle occupant are therefore at leastreduced, and the occupant is also protected by the side airbag when heis “out-of-position”.

FIGS. 2 and 3 illustrate a further exemplary embodiment of the occupantrestraint system according to the invention. In this variant, the sideairbag module 7, which comprises a gas bag and gas generator, isarranged in that side panel 12 of the vehicle which is arranged in frontof the side body. Said module can be fastened directly to the side bodyor to the panel. A fastening to stable parts which are arranged behindthe airbag module 7 in the direction of travel is preferred so that theairbag can be optimally supported during deployment.

As a rule, in vehicles which do not have rear doors, the side panel 12is provided with an armrest which has a cushion 15 for comfort purposes.This cushion is covered by a fabric 4. According to the invention, thiscushion 15 extends rearward and upward beyond the pure arm supportsurface and therefore forms a cover 11 for the side airbag module 7.

The cushion 15 is fastened to the panel 12, at least in the region ofthe cover 11, in such a manner that it is detached at least on one sideby the deployment of the airbag and can then be folded away to the sidewhen the airbag is released. The seam which faces the outside of thevehicle is preferably to be designed as an easily releasable connectionof this type. The cushion 15 thereby folds shut in the region of thecover 11 when the airbag is released toward the occupant and in theprocess affords the advantage described in detail in conjunction withthe exemplary embodiment illustrated in FIG. 1, so that the risk of adirect impairment of the vehicle occupant by the deploying airbag isconsiderably reduced.

1. An occupant restraint system located in a rear passenger compartmentof a motor vehicle, comprising a side airbag module which comprises agas bag and a gas generator and is arranged next to a side of a rearseat which faces the side body, a cover being provided in front of theside airbag module in the direction of travel, the cover including anelastically deformable material and being an integral component of aside member of the rear seat, wherein the side airbag module is fastenedto a partition wall arranged behind the rear seat and, duringdeployment, is supported on said partition wall.
 2. The occupantrestraint system as claimed in claim 1, wherein the cover consists offoam.
 3. The occupant restraint system as claimed in claim 1 wherein thecover is covered with a fabric.
 4. The occupant restraint system asclaimed in claim 3, wherein the cover is fastened releasably to the sidebody or the side panel.
 5. The occupant restraint system as claimed inclaim 4, wherein an airbag lid is provided between the foam cover andthe side airbag module.
 6. The occupant restraint system as claimed inclaim 5, wherein the cover forms the airbag lid.
 7. The occupantrestraint system as claimed in claim 6, wherein the side airbag moduleis arranged in such a manner that it is deployed forward, when lookingin the direction of travel.
 8. An occupant restraint system located in arear passenger compartment of a motor vehicle, comprising a side airbagmodule which comprises a gas bag and a gas generator and is arrangednext to a side of a rear seat which faces the side body, a cover beingprovided in front of the side airbag module in the direction of travel,wherein the cover includes elastically deformable material and is anintegral component of an arm support arranged in the region of the sidebody.
 9. The occupant restraint system as claimed in claim 8, whereinthe cover includes foam.
 10. The occupant restraint system as claimed inclaim 8, wherein the cover is covered with a fabric.
 11. The occupantrestraint system as claimed claim 10, wherein an airbag lid is providedbetween the foam cover and the side airbag module.
 12. The occupantrestraint system as claimed in claim 11, wherein the cover forms theairbag lid.
 13. The occupant restraint system as claimed in claim 12wherein the side airbag module is arranged in the side panel.
 14. Theoccupant restraint system as claimed in claim 13, wherein the sideairbag module is arranged in such a manner that it is deployed forward,when looking in the direction of travel.
 15. The occupant restraintsystem as claimed in claim 14, wherein the arm support is fastenedreleasably to the panel at least in the region of the cover.
 16. Anoccupant restraint system located in the rear passenger compartment of amotor vehicle, comprising: a side airbag module including a gas bag anda gas generator and being arranged next to a side of a rear seat whichfaces a side body of the vehicle; and a cover in front of the sideairbag module in the direction of travel, wherein the cover includes anelastically deformable material and is an integral component of a sidemember of the rear seat, wherein the side airbag module is fastened to apartition wall arranged behind the rear seat and, during deployment, issupported on the partition wall.
 17. The occupant restraint system asclaimed in claim 16, wherein the cover includes a foam material.
 18. Theoccupant restraint system as claimed in claim 17, wherein the cover iscovered with a fabric.
 19. The occupant restraint system as claimed inclaim 18 wherein the cover is fastened releasably to the side body or aside panel.
 20. The occupant restraint system as claimed in claim 19,further comprising an airbag lid between the foam cover and the sideairbag module.
 21. The occupant restraint system as claimed in claim 20,wherein the cover includes the airbag lid.
 22. The occupant restraintsystem as claimed in claim 21, wherein the side airbag module isarranged in such a manner that it is deployed forward, when looking inthe direction of travel.
 23. An occupant restraint system located in therear passenger compartment of a motor vehicle, comprising: a side airbagmodule including a gas bag and a gas generator and being arranged nextto a side of a rear seat which faces a side body of the vehicle; and acover in front of the side airbag module in the direction of travel,wherein the cover includes an elastically deformable material and is anintegral component of the rear seat's arm support arranged near the sidebody.
 24. The occupant restraint system as claimed in claim 23, whereinthe cover includes a foam material.
 25. The occupant restraint system asclaimed in claim 24, wherein the cover is covered with a fabric.
 26. Theoccupant restraint system as claimed in claim 25, further comprising anairbag lid between the cover and the side airbag module.
 27. Theoccupant restraint system as claimed in claim 26, wherein the coverforms the airbag lid.
 28. The occupant restraint system as claimed inclaim 27, wherein the side airbag module is arranged in a side panel ofthe vehicle.
 29. The occupant restraint system as claimed in claim 28,wherein the side airbag module is deployable forward in the direction oftravel.
 30. The occupant restraint system as claimed in claim 29,wherein the arm support is fastened releasably to the side panel atleast in the region of the cover.